1. Field of the Invention
The present invention relates to an imaging lens assembly, and more particularly, to a compact imaging lens assembly used in portable electronic devices.
2. Description of the Prior Art
In recent years, with the popularity of mobile phone cameras, the demand for compact imaging lenses is increasing, and the sensor of a general photographing camera is none other than CCD (charge coupled device) or CMOS device (Complementary Metal Oxide Semiconductor device). Furthermore, as advanced semiconductor manufacturing technology has allowed the pixel size of sensors to be reduced and the resolution of compact imaging lenses has gradually increased, there is an increasing demand for compact imaging lenses featuring better image quality.
A conventional compact imaging lens assembly, utilizing two-piece lens structure for lower production costs, such as the one disclosed in U.S. Pat. No. 7,525,741, generally comprises two lens elements in the imaging lens assembly. Due to its limited ability to correct aberrations of the two-piece lens structure, it cannot satisfy the needs of higher level camera modules. On the other hand, it cannot stay compact when the total track length increases from allocating more lens elements for better image quality.
In order to obtain better image quality while being compact, an imaging lens assembly with three lens element structure becomes a favorable solution. U.S. Pat. No. 7,436,603 provides an imaging lens assembly with three lens element structure comprising, in order from the object-side to the image side, a first lens element with positive refractive power, a second lens element with negative refractive power, and a third lens element with positive refractive power, which comprises the lens arrangement of a triplet. Although such an arrangement can correct most of the aberrations, it requires a longer total optical track length, resulting the lengthening of the lens structure corresponding to the total optical track length, and is unable to satisfy the need for a lighter and compact camera lens assembly.
Therefore, a need exists in the art for an imaging lens assembly that features better image quality, maintains a moderate total track length and is applicable to compact portable electronic products.